Projectile



April 7, 1936. w. T. MOORE 2,036,292

PPPPPPPP LE A. @wf/M Atturnay PatentedI Apr. 7, 1936 y UNiTED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the paymentv to me of any royalty thereon.

This invention relates to a projectile.

From the standpoint of interior ballistics it is desirable to have a bulletfwhich has little mass but great cross-sectional area and consequently low sectional density in order to give 10 the powder gases a suficientl area upon which to push. From the standpoint of exterior ballistics it is desirable to have a bullet of the smallest cross-sectional area with the greatest sectional density. Y

The purpose of this invention is to provide a bullet which .is capable of being permanently re-shaped during its passage through the bore ofa gun barrel whereby it may conform to the requirements of interior and exterior ballistics. As a consequence, higher muzzle velocities may be obtained with the same chamber pressures now employed in conventional weapons,.or conversely the samamuzzle velocity may be obtained with 'lower developed pressures.

25 More specifically the invention consists in providing a bullet with an enlarged hollow base which is permanently re-shaped upon passing through the forming die of the barrel to produce ns which stabilize the bullet 'in ight.

30 To .these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claims-forming a part of this 'specication A practical embodiment of the invention is illustrated in the accompanying drawing, where- 1n:

Fig. 1 is a longitudinal sectional View of the bullet before passing through the gun. barrel. Fig. 2 is a rear end view of Fig. 1.

Fig. 3 is a view in side elevation of the bullet after passing through the barrel.

Fig. 4 is a rear end view of Fig. 3.. Fig. 5 is a longitudinal sectionalview of a 5 gun barrel for re-shaping the bullet.

Figs.- 6, '1,` 8 and 9 are sectional views on the .respective lines of Fig. 5. I

Fig. is a View in side elevation bullet re-shaped in a diierent manner.

of the of a body 5 and anintegral enlargedhollow base 6 constituting'al cup-shaped tail, 'approximately one-half as long as the body. The diameter of the rear end of '.theqbaseGwiseapproximately 55 twice the maximum diameter of the body 5.

Referring to Figs. 1 and 2 the bullet consists irrespective of their caliber.

The base 6 isnformed with a hemi-spherical cavity l which is in communication with a cavity 8 provided axially in the rear portion of the body and having a length equal to approxi--- mately one-third the length of the body. The 5- wall of the base 6 is' of a`gradual1y reduced thickness from'its front to its rear end. ,The base'6 is composed of a metal which is deform able and which may be permanently re-shaped into ins of any desired character. I 10 Referring to Figs. 5 to 9 a gun'barrel 9 has a bore in which lands l0 are gradually widened from breech to muzzle and at the same time gradually converged towards the axis of bore. with the result that the grooves Il are gradually narrowed and deepened towards the muzzle. The twist of the riing is only about one-fourth to one-half of Aa turn in the entire length of the barrel.

The gun barrel constitutes a forming .die which acts on'the base 6 to permanently reshape it, providing iins I2 as shown in Figs.' 3 f and 4, and reducing the cross-sectional area of the base. During the travel of the bullet through the greater part of the barrel its body 5 is out of contact with the bore. At the muzzle 'of the barrel the lands l0 are preferablydimensioned to slightly `contact the body 5 and thereby give it lateral stability. s Y

Approximate calculations of `the interior bal-.30 listics of this bullet made in comparison with a conventional .30 caliber bullet are as follows, assuming bullets oi the same weight and the same developed pressures'. Where the diameter of vthe base 6 is twice that of the body 5, then 35 `re-shaped will depend on the nature and character of the lands and grooves of the gun barrel.

While the present bullet has been illustrated and described as having four ns it is obvious that the number and shape of the fins may be readily varied. As shown in Fig.- l0 the base Sa may be reduced, in diameter and drawn out so as t0 reduce the cross-sectional area of the bullet.

' While the invention iinds its most practical application for bullets, the principles set forth are equally applicable to all'classes of projectiles to the .3o caliber 40 i 1. A projectile comprising a body having a cavity in its rear end, a hollow base on the body having a diameter approximately twice the di ameter of the body and lhaving a hemi-spherical cavity opening into the cavity of the body, the wall thickness of the base being gradually reduced towards its rear end, and said base being .permanently re-shapeable upon passage of the projectile through a gun barrel.

2. A projectile comprising a body having a I cavity in its rear end, a hollow base on the body 'the body, and comprising the sole bearing surface throughout the major portion iof the length of .the barrel the wall thickness of the base being gradually reduced towards its rear end, and said1 base being permanently re-shapeable upon passage of the projectile through the gun barrel.

4; A projectile adapted to be red through a gun barrel comprising a body, a hollow base on the body having a diameter approximately twice the diameter of the body and having a heini-spherical cavity, the wall thickness of the base being gradually reduced towards its rear end, and said base comprising the sole bearing surface throughout the major portion of the length of the gun barrel and being permanently re-shapeable upon passage of the projectile through/the gun barrel.

5.y A projectile adapted to be red through a gun barrel comprising a body, a hollow base on the body having a diameter approximately twice the diameter of the body, the wall thickness of the base being gradually reduced towards its rear end, and Ysaid base comprising the sole bearing surface throughout the major portion of the length of the gun barrel and being permanently re-shapeable upon passage of the projectile through the gun barrel.

6. A projectile adapted to be red through a Vgun barrel comprising a body, a hollow base on the body, the wall thickness of the base being gradually reduced towards its rear end, and said base 'comprising the sole bearing surface throughout the majo-r 'portion of the length of the gun barrel and being permanently reshapeable upon passage of the projectile through the gun barrel.

WILEY T. MOORE. 

